org.apache.hadoop.io.compress
Class CompressionCodecFactory

java.lang.Object
  org.apache.hadoop.io.compress.CompressionCodecFactory

public class CompressionCodecFactory
extends Object

A factory that will find the correct codec for a given filename.

Field Summary

static org.apache.commons.logging.Log

LOG

Constructor Summary

CompressionCodecFactory(Configuration conf)
Find the codecs specified in the config value io.compression.codecs and register them.

Method Summary

CompressionCodec	getCodec(Path file) Find the relevant compression codec for the given file based on its filename suffix.
static List<Class<? extends CompressionCodec>>	getCodecClasses(Configuration conf) Get the list of codecs listed in the configuration
static void	main(String[] args) A little test program.
static String	removeSuffix(String filename, String suffix) Removes a suffix from a filename, if it has it.
static void	setCodecClasses(Configuration conf, List<Class> classes) Sets a list of codec classes in the configuration.
String	toString() Print the extension map out as a string.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

LOG

public static final org.apache.commons.logging.Log LOG

Constructor Detail

CompressionCodecFactory

public CompressionCodecFactory(Configuration conf)

Find the codecs specified in the config value io.compression.codecs and register them. Defaults to gzip and zip.

Method Detail

toString

public String toString()

Print the extension map out as a string.

Overrides:

toString in class Object

getCodecClasses

public static List<Class<? extends CompressionCodec>> getCodecClasses(Configuration conf)

Get the list of codecs listed in the configuration

Parameters:

conf - the configuration to look in

Returns:

a list of the Configuration classes or null if the attribute was not set

setCodecClasses

public static void setCodecClasses(Configuration conf,
                                   List<Class> classes)

Sets a list of codec classes in the configuration.

Parameters:

conf - the configuration to modify

classes - the list of classes to set

getCodec

public CompressionCodec getCodec(Path file)

Find the relevant compression codec for the given file based on its filename suffix.

Parameters:

file - the filename to check

Returns:

the codec object

removeSuffix

public static String removeSuffix(String filename,
                                  String suffix)

Removes a suffix from a filename, if it has it.

Parameters:

filename - the filename to strip

suffix - the suffix to remove

Returns:

the shortened filename

main

public static void main(String[] args)
                 throws Exception

A little test program.

Parameters:

args -

Throws:

Exception